1. Field of the Invention
The present invention pertains to the art of refrigerators and, more particularly, to a variable position damper that can be selectively controlled to deliver cooling air into a freezer compartment and/or a fresh food compartment of a refrigerator.
2. Description of the Related Art
There are many systems for delivering cooling air into refrigerator compartments to maintain selected temperatures. In some cases, the refrigerator is provided with two cooling systems, one system delivering cooling air into the freezer compartment and another, separate system, delivering cooling air into the fresh food compartment. While effective, the manufacturing costs associated such refrigerators are high. Moreover, operating multiple cooling systems reduces an overall efficiency of the appliance.
In other cases, cooling air is first delivered into the freezer compartment to establish a freezer compartment temperature. With this arrangement, cool air is directed from the freezer compartment into the fresh food compartment to establish and/or maintain a desired fresh food compartment temperature. Typically, the cool air is guided through a passage that interconnects the freezer and fresh food compartments. A damper is typically arranged within the passage to selectively allow cooling air to pass into the fresh food compartment when necessary, and close off the passage absent a need for cooling air. Efficiency gains were realized with the use of variable position dampers that control how much cooling air is passed into the fresh food compartment. Additional efficiencies were realized with the use of variable capacity compressors and variable speed fans. As a demand for cooling is sensed, instead of operating at maximum output, the compressor and fans are driven at a speed sufficient to satisfy a particular cooling demand.
Unfortunately, the energy savings realized in known systems that employ dampers is limited. Usually, most of the cooling demand is required in the freezer compartment. In situations where the fresh food compartment requires a small adjustment, the cooling system needs to overdrive the freezer compartment in order to have sufficient cooling air to siphon off to the fresh food compartment. In some cases, a demand for cooling in the fresh food compartment is not met until the freezer compartment also requires cooling. In order to address this problem, some manufacturers position the damper between the cooling system and both the freezer and fresh food compartments. In this configuration, the damper is positioned to deliver cooling air into one or the other compartment depending on a particular cooling demand.
In one such arrangement, the damper is positioned at an opening in a side wall of an air plenum. The damper is shifted to allow cooling air into one, the other or both of the freezer and fresh food compartments. While effective, the particular geometry of the damper leads to inefficient air transfer. Back pressure, created by turbulences in the air flow, impedes delivery of cooling air into one or the other compartment. When the damper is positioned to allow air to pass into both compartments, the back pressure results in the volume of air flowing into each compartment to be unregulated.
Based on the above, despite the existence of refrigerator air delivery systems in the prior art, there still exists a need for a refrigerator air delivery system that employs a variable position damper to deliver air to multiple refrigerated compartments either individually or simultaneously. Moreover, there exists a need for a variable position damper that includes an air scoop to reduce air turbulence and efficiently deliver cooling air into freezer and/or fresh food compartments.